RESIDENTS in two states were battling against severe weather yesterday that brought record floodwaters, torrential rain, 100km/h winds and hailstones as big as golf balls.

Emergency services in the southwest Queensland town of St George were last night preparing for a flood peak expected to inundate 80 per cent of the town, as Melbourne mopped after a severe storm cell that wreaked havoc.

The Balonne River was already at a record 13.26 metres yesterday afternoon and the weather bureau has predicted it could peak at 13.5 metres - the highest level since recordings began in 1890.

About 40 of the town's 2800 residents were evacuated to a makeshift evacuation centre at the showgrounds. Residents from an aged care facility in the town, 500 kilometres west of Brisbane, were flown to the state capital.

Many St George residents, including Nationals Senator Barnaby Joyce, whose family home fronts the Balonne River, spent the day filling 4000 sandbags.

About 25 homes went under but the community appeared to be spared the worst last night. …

Further south, residents of Cunnamulla braced themselves for a drenching more severe than the floods of 2008 when waters peaked at 9.91 metres. Cunnamulla is expected to be hit with a major flood peak of 10 metres early this week.

An area greater than that of the state of Victoria has been affected by the flooding in Queensland's south. In Melbourne, hail blanketed the city like snow as a thunderstorm ripped through the capital, forcing the cancellation of major events and damaging dozens of buildings. A total of 26 millimetres of rain fell in less than an hour, bringing emergency services to a grinding halt.